The present invention pertains to an assembly or device for radially stabilizing a drill string which includes rotating tubular bodies such as oil field drill bits, drill collars, and the like which tend to radially vibrate or whip during operation.
In the operation of each embodiment of the present invention, as in the operation of prior art devices, the assembly is rotated in a borehole as in drilling an oil or gas well, and drilling fluid is pumped in the usual manner downward through a central axial passage formed through the assembly. The drilling fluid returns upward through the borehole annulus on the outside of the assembly. As in normal practice, the diameter of the borehole is only slightly larger than the assembly, providing only sufficient running clearance for free rotation of the assembly.
However, in the operation of prior art devices, the running clearance increases due to wear of the outside of the drill string. Since the degree of whip or radial vibration of a drill string increases as the running clearance increases, harmful vibration or whip occurs with prior art devices. As will be shown in the following explanation, the present invention provides means to prevent excessive running clearance and thus will prevent whip or radial vibration of a drill string.